1. Field of the Invention
The invention concerns a method for fabricating a screen-like shear foil for an electrically operated dry shaving apparatus with elevations on its surface that is turned towards the skin.
Such shear foils have the advantage that they slide on the skin easily even if the skin is greasy or moist. This is not only perceived as pleasant while shaving, but the quality of the shave is considerably improved thereby.
2. Description of the Prior Art
The DE-AS No. 30 03 379 discloses a method for fabricating a shear foil with elevations for an electrically operated dry shaving apparatus. Here, a metal plate (50) is covered with the pattern (51) of the hole area, and subsequently an intermediate metal foil (53) is built up by electroplating at the points (52) which correspond to the grid of the screen. The thickness (54) of these points is larger, corresponding to the elevations of the hole edges, than the thickness (55) of the covering (51) of the hole area. Finely distributed solid particles (56) are applied to the surface of the intermediate metal foil (53). Only after this is the shear foil (57) deposited by electroplating in well-known fashion, and is removed from the intermediate metal foil (53) by being torn off (FIG. 13).
The known method has the disadvantage that elevations are formed not only on that surface of the shear foil which is turned towards the skin but also in the region of the hole edge. This can result in undercuts, which, on the one hand, make it much more difficult to tear off the shear foil and, on the other hand, frequently yield a negative cutting angle at the cutting edges of the hole-edge elevations. This has an unfavorable effect on the cutting behavior.